A fuel feed apparatus disclosed in JP-A-9-268957 is capable of stably feeding fuel from an inside of a fuel tank to the outside, even when an amount of fuel received in the fuel tank decreases. The fuel feed apparatus includes a sub-tank receiving a fuel pump and the like. The sub-tank is supported by a supporting member such that the sub-tank is axially displaceable relevant to a lid member that is provided to an opening formed in the fuel tank.
A biasing means such as a spring is provided between the sub-tank and the lid member such that the spring urges the sub-tank and the lid member in the direction, in which the sub-tank and the lid member are apart from each other. Therefore, the sub-tank can be pressed onto the inner bottom plane of the fuel tank, regardless of the inner volume of the fuel tank. As a result, fuel remaining around the sub-tank can be stably drawn into the sub-tank, even when liquid level of fuel decreases in the fuel tank.
A conventional fuel feed apparatus has supporting members such as metallic pipes that are arranged on both radially outer portions of the sub-tank. The biasing means is provided to the outer circumferential side of each of the supporting members arranged on both the radially outer portions of the sub-tank. Alternatively, the biasing means may be provided to the outer circumferential side of one of the supporting members, so that the number of components can be reduced. However, when the biasing means is provided to one of the supporting members, resilient force applied to both the lid member and the sub-tank becomes unstable. That is, the lid member and the sub-tank lose balance therebetween due to difference of resilient force applied by the biasing means. Accordingly, it is difficult to assemble the lid member to the sub-tank on the side of the supporting member, to which the biasing means is provided, due to instability of resilient force applied by the biasing means.
Besides, when the biasing means is provided to only one of the supporting members, the sub-tank may be inclined due to instability of resilient force. As a result, the supporting member, on which the biasing means is not provided, may be inclined. In this situation, the supporting member, on which the biasing means is not provided, slides against a supporting portion, which slidably supports the supporting member, in an inappropriate angle. Accordingly the supporting member does not smoothly slide with respect to the supporting portion, and the supporting member and the supporting portion are abraded with each other. Besides, the sub-tank may not be pressed onto the inner bottom plane of the fuel tank, and fuel may not be properly pumped into the sub-tank.